2,926 reputation
615
bio website
location
age
visits member for 2 years, 3 months
seen Dec 12 at 18:40

Dec
1
awarded  Nice Answer
Nov
30
comment Wind Map Artwork
Colouring according to the wind scale may be accomplished with, for example, StreamColorFunction->(ColorData["DarkRainbow",#5]&). Slot #5 corresponds to Norm[{vx,vy}].
Nov
27
comment Mathematica, animations, and external ray tracing programs
Unfortunately, not that easy. Export the Mathematica graphic as pov code, then edit that code with clock functions. Depends on how simple your original graphic is. For my images, I use Mathematica to write strings of pov primitives directly. That way I have full control, and get the colours too.
Nov
26
answered Mathematica, animations, and external ray tracing programs
Nov
20
answered How to check if a line segment intersects with a polygon?
Nov
9
answered How to create a Poincare disk type kaleidoscope in Mathematica?
Oct
10
comment Solving Fredholm Equation of the first kind
I defer to the mathematicians in the group, but the Volterra integral equation mentioned in the duplicate question is a Fredholm integral equation of the second kind, and of special convolution form. That equation has an unknown left-hand side which also appears under the integral. The Fredholm integral equation of the first kind in this question has a known left-hand side which does not appear under the integral, and is not explicitly of convolution form. Duplicate?
Oct
9
answered Solving Fredholm Equation of the first kind
Oct
7
awarded  Necromancer
Oct
6
awarded  Necromancer
Sep
23
answered Rotated Rectangles
Sep
18
awarded  Nice Answer
Sep
17
revised Why does Fourier give a shifted frequency?
added 21 characters in body
Sep
9
comment Error computing sum of sum of digits
I really want to use your technique because it is creative thinking plus blinding speed; however, cumDigitSum[12,10] returns 49 ?? I've tried to understand your approach in order to suggest an edit to the code, but as yet cannot.
Sep
9
comment Error computing sum of sum of digits
Hi Daniel: I can't get your function to give the same results as Mr.Wizard's. The "6" in b^6 looks suspicious...
Sep
3
answered How to speed up my Project Euler code
Sep
1
awarded  Yearling
Aug
21
answered To inscribe a circle in a given triangle
Aug
7
comment Why does Fourier give a shifted frequency?
@LeoFang Arbitrary resampling of a signal is not always possible in the real world. Given only the original 201-point signal, tapering removes the problem, as I suggested, as JamesCunnane suggested in a comment (recommending trend removal as well), and as Mr.Wizard suggested in an answer. Again, this does not mean your answer is wrong.
Aug
7
comment Why does Fourier give a shifted frequency?
@LeoFang I'm sorry about your downvote too, especially since you do not say how or why my explanation is wrong. I will not downvote your answer, you could do that yourself because both our explanations are the same, as stated by xslittlegrass in the comment above. You and I both suggest sampling more points to solve the problem. In my case 297 points, in yours 314, a trivial difference caused by the low-amplitude higher-frequency component. Can you see that, for harmonic signals, an incomplete period is the same as mismatched endpoint amplitudes?